Light fixture with internal connection zone

ABSTRACT

An electrical light fixture (1) having a tubular arm (2) with an opening (20) formed in a wall portion to define a connecting zone (21) in which internal lamp wiring (13) is connected to an external power supply line (25) which extends through a cover (23) for the opening.

TECHNICAL FIELD

This invention relates to a light fixture of the type having a tubulararm with a light supported near one end of the arm, such as are utilizedin industrial applications for lighting railroad or truck loading docks.

BACKGROUND ART

Industrial light fixtures including a tubular arm, such as an arm madeof one or more square channel elements, with one end of the arm attachedon a suitable mounting bracket, an electrical lamp at the other end ofthe arm, and wiring enclosed within the tubular arm and leading to thelamp must be connected to an electrical power supply line when they areinstalled in the desired area. The typical prior art system forconnecting the power supply line to the internal lamp wiring of thelight fixture has been to attach a junction box to an external surfaceof the arm and make the connection between the power supply line and theinternal lamp wiring in the junction box.

DISCLOSURE OF INVENTION

My present invention relates to a light fixture of the type having atubular arm wherein an opening is formed in a selected portion of thearm to provide a connecting zone inside the arm, a cover plate isapplied over the opening, in the arm, and the connection between thepower line and the internal lamp wiring of the light fixture is madewithin the connecting zone underneath the opening. This constructioneliminates the need to use an external junction box on top of the armand yet provides a safe and neat system for making the requiredconnection.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a light fixture incorporating thepresent invention;

FIG. 2 is a vertical sectional view of a portion of the light fixture;

FIG. 3 is a top view of a portion of the light fixture illustrating theopening formed in the tubular arm of the fixture; and

FIG. 4 is a perspective view similar to FIG. 1 except with a portion ofthe light fixture broken away illustrating a prior art system for makingthe connection between the power supply line and the internal wiring ofthe light fixture.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 illustrates an industrial electrical light fixture 1 having atubular arm 2 comprising an inner section 2a and an outer section 2bpivotally connected together about a pivot pin 3. The tubular arm 2 mayhave only one section or more than two sections, and the connectionbetween sections 2a and 2b may be a swivel type connection if desired.The arm 2 is shown as being made of four-walled metal channel sections,which can be square or rectangular in cross-section; also, the tubulararm can have an oval or circular cross-section. The inboard end of armsection 2a is pivotally supported about a pin 5 (see also FIG. 2) thatextends through a pivot tube 6 supported in a bracket 7. The bracket 7is adapted to mount the light fixture 1 on a wall or other suitablesurface. Brace 8 may extend from the lower end of the bracket to theunderside of the arm section 2a as shown. End caps 9 close each end ofthe arm sections 2a and 2b.

At the other end of the arm 2, an electric light 10 is supported in alamp housing 11 carried in U-shaped bracket 12 that is secured near theouter end of arm section 2b. Lamp wiring 13 is connected to the lamp 10,led into sthe arm section 2b at 14 and strung inside the arm to exit at15, and then led into arm section 2a at 16 and strung inside the armsection 2a towards its inboard end. Thus, at least part of the lampwiring 13 is arranged internally of the tubular arm 2. The internal lampwiring 13 is typically three conductor electrical wire to provide agrounded cord. Suitable strain connectors are employed at the points14-16 where the internal lamp wiring passes through a wall of the armsections 2a and 2b in accordance with the usual practice.

The light fixture 1 as described to this point is of a typicalconstruction which has been sold in large numbers by the assignee ofthis application. The present invention relates to the manner in whichthe internal lamp wiring 13 is connected to an electrical power supplyline.

Turning now to FIG. 3, an opening 20 is formed in the top wall of thearm section 2a near the inner end thereof attached to the bracket 7. Theinterior of the arm section underneath the opening forms a connectingzone 21 which will be utilized to make the connections with a powersupply line as described hereinafter. The internal lamp wiring 13 hasconductor ends 22 disposed within the connecting zone 21 as shown in thedrawing. A cover 23 (see FIGS. 1 and 2), illustrated as comprising aflat plate, is provided which is large enough to cover the opening 20and has end portions extending beyond the opening through whichfastening means such as self-tapping screws 24 extend to attach thecover to the top wall of the arm section. Electrical power supply line25, illustrated herein as a three-wire conductor, passes through thecover 23, with a suitable strain connector 26 being insertedtherebetween. The power supply line 25 is connected to the ends 22 ofthe internal lamp wiring 13 within the connecting zone 21 underneath theopening 20 in the usual manner as illustrated in FIG. 2.

PRIOR ART

FIG. 4 illustrates a prior art manner in which the connection between anelectrical power supply line and internal lamp wiring has been made. Anexternal junction box 30 is attached to one end of the arm 2 of a lightfixture, near the bracket 7. The supply line 25 is led into the junctionbox 30 through a side wall thereof, and the internal lamp wiring 13 isled through the bottom of the box so that the connections between thetwo are made inside the junction box. The prior art approach thusrequired the use of an extra accessory, i.e. the junction box 30, andmade the connections externally of the arm of the lamp fixture.

In contrast to the prior art system, the present invention provides aninternal connecting zone inside the tubular arm of a light fixturewithin which the connections are made between an electrical power supplyline and the internal lamp wiring leading to the lamp element. This isaccomplished by providing an opening in the wall of the tubular arm anda cover for the opening, and then leading the supply line through thecover to be connected to the internal lamp wiring within the zonedefined by the opening. This provides an especially neat arrangement andeliminates the need for an external junction box as has been typicallyused before. At the same time, easy access is provided so that therequisite electrical connections can be made in a convenient manner.Also, there is less danger of accidental damage to the power lineconnection since it is made internally of the arm of the fixture ratherthan in an exposed exterior junction box. Prior art fixtures using ajunction box have the power supply line leading through a side of thebox, thereby forming a rather large loop of wire along one side of thelight fixture which can sometimes be a problem. This is avoided with thepresent invention by forming the opening in the top wall of the tubulararm as shown in the drawings, which keeps the power supply line abovethe fixture instead of on one side of it; this new arrangement minimizesthe potential for interference between the fixture and a loop of thesupply line.

I claim:
 1. In an electrical light fixture of the type including atubular arm, an electric light supported on the arm, and lamp wiringconnected to the electric light and being at least partly arrangedinternally of the tubular arm, the improvement comprising:an openingformed in the tubular arm to define thereunder a connecting zone withinthe arm; the lamp wiring having conductor ends disposed within theconnecting zone; a cover attached to the tubular arm over the opening;and an electrical power supply line extending through the cover andconnected to the conductor ends of the lamp wiring in the connectingzone within the arm.
 2. The electrical light fixture of claim 1wherein:the tubular arm is a four-walled channel element, the opening isformed in one wall of the channel element, the cover is a flat platehaving end portions extending beyond the opening, and fastening meansextend through the end portions to attach the plate to said one wall ofthe channel element.
 3. An electrical light fixture according to claim 1or 2 wherein:the opening is formed in a top wall of the tubular arm.